MySQL

In the borrowing table and the reader table there is such a relationship, if you add a data in the borrowing table, the corresponding cumulative borrowing field in the reader table is increased by 1, if you delete a data in the borrowing table, the

Background introduction:When we installed a few databases by default after we had initialized MySQL, what would be the role of these databases?mysql> show databases;+--------------------+| Database |+--------------------+| Information_schema ||

Directly on the code:#!/usr/bin/env python#coding:utf-8import xlwtimport mysqldbimport datetimedatabase =  mysqldb.connect (host= ' 192.168.1.30 ', user= ' root ', passwd= ' 123456 ', db= ' CRM ') #设置字符集database. Set_character_ Set (' UTF8 ') cursor 

Many friends in MySQL think that the field auto_increment type self-increment ID value can not be modified, in fact, this understanding is wrong, the following describes the MySQL self-increment ID starting value modification and setting method.The

First:Check if Bin_log is turned onMysql> Show variables like ' Log_bin ';+---------------+-------+| variable_name | Value |+---------------+-------+| Log_bin | On |+---------------+-------+How does the Binlog function open?[[email protected] 3306]#

By default, the MySQL database is not allowed to be accessed remotely.You need to use the following steps to turn on MySQL remote access permissions:First mysql-u root-p login mysql command line,then use MySQL;After opening permissions:GRANT all

Transaction: TransactionMultiple SQL statements, either executed at the same time, or not executed at the same timeA transaction is a set of atomic (SELECT) query statements, and multiple queries are treated as a separate unit of workAcid testing:

MySQL based on the field of the group query, the same field of data, only one display, if you want to make this field of all the data, display in a row, you can use the Group_contat function in the query, the default data merge with commas, separate6

MySQL's alter statement usage summary1: Delete ColumnsALTER table "table name" DROP "column name"2: Add columnsALTER table "table name" ADD "column name" INT not NULL COMMENT ' comment description 'altertable tableName addnewColumn varchar(8)

MySQL is the most popular relational database management , MySQL is the best RDBMS in Web application: Relational database management systemWhat is a database?A database is a warehouse that organizes , stores , and manages data in accordance with a

The partition in MySQL has range, list, hash, key four kinds of partitioning methodsWe introduce the Range method here, and others can digestPartitioning an existing table (range mode)ALTER table name PARTITION by range (field name) (PARTITION

[High-Performance MYSQL post-read casually] about the transaction isolation level, after mysql readsI. Lock types There are many types of locks in MySQL, including common table locks and row locks, and new Metadata locks. Table locks apply locks to

Mysql and mysql This article uses the SQL Sample Code to introduce how the mysql database converts rows and columns. Let's just look at the sample code. Original table: Table name: user -------------------------------------- name | course | grade

MySQL cannot restart and reports the following error: Warning: World-writable config file '/etc/my. cnf' is an ignored solution: my. cnfisignored Problem Analysis The command for shutting down the database finds that mysql cannot be shut down,

MySQL cannot be started in Windows, and WindowsMySQL cannot be started.Problem description:From MySQL 5.7 on the internet, execute start mysqld in the bin directory. the pop-up cmd window will disappear, and you cannot see what the error is. Mysqld -

NodeJS uses mysql and nodejsmysql 1. Prepare the environment Manually add database dependencies: Add "mysql": "latest" in dependencies of package. json ", { "name": "news", "version": "0.0.0", "private": true, "scripts": { "start": "node

InnoDB: Lock & Transaction, innodblock InnoDB is an Engine that supports transactions. To ensure ACID of transactions, you must use Lock. Just like programming in Java, to ensure the thread security of data, the Lock will inevitably be used.

MySQL check command in Linux (detailed description) and linuxmysqlcheck The mysqlcheck client tool can check and repair MyISAM tables, and optimize and analyze tables. In fact, it integrates the functions of check, repair, analyze, and optimize in

How to install mysql5.7.16 (decompressed version) and win10mysql5.7.16 on win10 Note: This article describes how to install the decompressed version. Installation tutorial Download mysql Address: http://dev.mysql.com/downloads/mysql/

How can I solve the 10055 error message when MYSQL cannot be connected? mysql10055 Solution: (the following content is my original Practice) To sum up, it should be the number of connections, so what are the number of connections on the server: 1.